What number makes this equation true? $960 - $
$960 -{{?}}= 581$ ${581}$ ${960}$ $-?$ Let's start by subtracting hundreds from ${960}$ until we get as close to ${581}$ as possible without going below ${581}$. $\begin{aligned} {960} -100}=860\\\\ {860} -100}= 760\\\\ {760} -100}= 660 \end{aligned}$ If we subtract $3 \text{ hundreds}}$, or $3 00}$, we reach $660$. We cannot subtract any more hundreds without going below ${581}$. ${581}$ ${960}$ ${660}$ $-300$ Next, let's subtract tens from $660$ until we get as close to ${581}$ as possible without going below ${581}$. $\begin{aligned} 660 -{10}=650\\\\ {650} -{10}= 640\\\\ {640} -{10}= 630\\\\ {630} -{10}= 620\\\\ {620} -{10}= 610\\\\ {610} -{10}= 600\\\\ {600} -{10}= 590 \end{aligned}$ If we subtract ${7 \text{ tens}}$, or ${70}$, we reach $590$. We cannot subtract any more tens without going below ${581}$. ${581}$ ${960}$ ${660}$ ${590}$ $-300$ $-70$ Finally, how many ones should we subtract from $590$ to get to ${581}?$ $590 -{9}={581}$ ${581}$ ${960}$ ${660}$ ${590}$ $-300$ $-70$ $-9$ We subtracted $3 \text{ hundreds}}$, ${7 \text{ tens}}$, and ${9\text{ ones}}$ from ${960}$ to get to ${581}$. $3 00}+{7 0}+{9}={379}$ ${581}$ ${960}$ ${660}$ ${590}$ $-300$ $-70$ $-9$ $-379$ $960 -{379}= 581$